Torch tip



Patented June 20, 1944 TORCH TIP Elmer H. Smith, Minneapolis, Minn.,assignor to Smith Welding Equipment Corporation, Minneapolis, Minn., a.corporation of Minnesota Application July 31, 1941, serial N3. 404,849

1 Claim.

This invention relates to new and useful 1111-' provements in torch tipsand more particularly to such tips adapted for burning hydro-carbongases, usuch as propane, butane, and other gases of a similar character.

In the manufacture of torch tips for cutting purposes, it is importantto arrange the precarbon gases, it is therefore highly desirable thatthe preheating -fuel ducts be arranged in close relation to the centralcutting gas passage, whereheating fuel orifices, which usually surroundIthe central cutting gas passage, as close to the cutting g-as passage aspossible, in order that a highly concentrated preheating flame may beprojected directly onto the surface area subsequently to be cut by thecutting flame. The cutting operation cannot be successfully starteduntil the surface or area to be cut has been heated to a kindlingtemperature. It is now common practice to construct a cutting torch oftwo parts or members, one member fitting within the other member. Theinner or core member'usually has a central cutting gas passage extendingthe full length thereof, and`a plurality of preheating fuel orices areprovided around the cutting passage at the tip of the torch. 'Ihesepreheating fuel orifices or ducts may be formed in various ways asdisclosed in my Patent No. 2,215,019, issued September 17, 1940, and nwPatent No. 2,254,757, granted to me on September 2, 1941.

Torch tips designed for burning hydro-carbon gases, such asv propane,butane, and the like,

must have the preheating fuel orifices at the tip Vof the torch disposedin close relation to the central or cutting gas passage, in order thatthe preheating fuel gas projected from the tip will be closelyconcentrated at the tip of the torch,

whereby the area to be cut may be quickly heated i to a kindlingtemperature before starting the cutting operation.

Heretofore, it has also been common practice to make the inner or coremember of a metal, such as brass, which more readily lends itself tocutting or grooving than copper, it 'being ali most impossible to millor cut small slots or grooves in the periphery of a small copper corebecause of the inherent characteristics of such metal. Copper has a muchhigher melting point than brass and therefore is more desirable for usein the construction of torch tips. By making both the outer and innermembers of copper, the coefficient of expansion of the two members willobviously be identical, and the walls of the two members may thereforebe swaged into intimate and permanentl contact in the formation of thetip, Without danger of the joints between the two members loosening up.

In cutting tips designed -for burning hydro? by the preheating name maybe projected therefrom 'and in such a manner as to form substantially acontinuous wall oi' gas around the path of the cutting flame, wherebythe preheating.

ame may be concentrated to a small area directly in line with thecutting flame, subsequently to be projected from the tip, when the metalhas been heated to the proper temperature for cutting.

An object of the present invention therefore is to provide a cutting tiphaving the preheating fuel orifices at the cutting end of the tipdisposed in close relation to the cutting gas passage, and the sides ofsaid orifices towards the axis of the cutting gas passage beingrelatively wider than the wall portions circumferentially separatingsaid orifices, whereby a highly concentrated preheating flame may beprojected from the torch tip.

A further objectiis to provide a torch tip comprising an youter tubularmember having a restricted bore at one end and an inner or core memberbeing fitted within said tubular member and having a reduced cylindricalend portion f1tting in said bore, the wall of said bore beingvprovidedwith a plurality ofV substantially' V-shaped longitudinally extendinggrooves having their wider sides disposed towards the center of the tip,whereby the preheating fuel flame projected from the tip will formsubstantiallyl a continuous wall around the cutting gas passage ororifice.

A further object is to provide a torch tip comprising an outer tubularmember having a restricted bore at one end whose wall is provided with aplurality of v-shaped grooves extending lengthwise of the bore andhaving their apexes pointing outwardly from the axis of the tip, insomewhat the formation of a star, whereby narrow, elongated ridges areprovided between said grooves adapted to engage the periphery of thereduced end portion ofthe inner core member, which is fitted into thetubular member, and which inner member has a central cutting gas passagetherein.

A further object, is toprovide a torch tip of the class described,comprising an outer tubular member having a restricted bore at one endformed with a plurality of longitudinally extending V-shaped grooves, byinserting a grooved mandrel in said bore and swaging the tubular memberto force the metal constituting the wall of the restricted bore into thegrooves in said mandrel, whereby the wall of said bore is provided witha plurality of V-shaped grooves separated by tooth-like ridges, and acore member having a longitudinally extending cutting gas passagetherein being provided with a reduced cylindrical end portion adapted tobe fitted tinto said grooved bore, after which the outer member is againswaged to force the ridges of the bore into intimate contact with theperiphery of said reduced portion, whereby a plurality of preheatingfuel gas orifices are provided which are disposed in relatively closerelation to the cutting gas passage, and from 'which a highlyconcentrated preheating flame may -be' directed from the torch tipdirectly onto the area subsequently to be engaged by the cutting flame.

A further object is to provide a torch tip composed of an outer memberhaving a core member fitted therein, and a plurality of fuel gasorifices being provided between said members at the cutting end of thetip, which are so constructed that the innerl member may be made ofcopper, as well as the outer member, thereby providing a torch` tipwhich is not likely to become damaged from extremely high temperatures,because an all copper tip has a relatively higher heat conductingcapacity than tips made from a combination of copper and brass, as isnow quite customary.

, vided with a. plurality of V-shaped grooves having their Wider opensides disposed towards the axis of the tip, whereby the reduced endportion of the inner or core member of the tip, when tted into thegrooved bore of. the outer member, will provide the inner walls of thepreheating orifices provided by the V-shaped grooves made in said bore,whereby the wall portions between the cutting gas passage of the coremember and the preheating fuel ducts may b e made extremely thin,whereby a highly concentratedl preheating flame may be projected fromthe tip directly onto the area to be cut by the cutting flamesubsequently to be projected from the tip, and whereby the tip may bepractically and efficiently used for burning hydro-carbon gases,` suchas hereinbefore referred to.

A further object is to provide an improved method of making torch tipscomposed of an outer tubular member and an inner core member, whichconsists in providing a restricted bore in one end of the tubularmember, placing a longitudinally grooved mandrel therein, and swagingone end of the outer member to force the wall of the restricted boreinto the bottoms of the grooves of the mandrel, 'whereby said bore isprovided with a plurality of longitudinally extend-- ing grooves, thenremoving the mandrel and insertng the cylindrical end portion of thecore member into said grooved bore, and again swaging the tubular memberto force the ridges sepa-y rating the grooves in said bore into intimatecontact with the periphery of the tubular member, whereby a plurality ofpreheating orifices are provided at the cutting end of the tip, whichare disposed in close relation to the central cutting gas passage f thetip.

:Other objects of the invention reside in the unique manner of formingthe grooves in the wall` of the restricted bore of the outer tubularmember and fitting the reduced end portion of the core member into saidbore, whereby the cylindrical' wall of the cutting gas passage at theend of the tip, may be made comparatively thin. to, thereby dispose thepreheating fuel gas orifices in relatively close relation to the centralcutting gas passage; in the arrangement of the grooves in the restrictedbore of the tubular member, whereby the adjacent end of the core membermay be relatively small in diameter, and whereby both the outer andinner members may be made of copper, thereby to provide an all coppertip; and, in the construction of such a tip which is simple andinexpensive in construction and which is particularly well suited forburning hydro-carbon gases.

Other objects of the invention will appear from the followingdescription and accompanying drawing and will be pointed out in theannexed claim.

In the accompanying drawing there has been disclosed a structuredesigned to carry out the various objects of the invention, but it is tobe understood that the invention is not confined to the exact featuresshown as various changes may be made `within the scope of the claimfollows.

In the drawing:

Figure 1 is a longitudinal sectional view showing the generalconstruction of my improved tip;

Figure 2 is a similar view with the outer tubular member only partiallyfitted onto the inner core member; I

Figure 3 is an enlarged cross sectional view on the line 3,--3 of Figure1;

Figure 4 is an enlarged cross-sectional Viewv on the line 4--4 of Figure2;

Figure 5 is an erid view of the completed tip; Figure 6 is a viewshowing the tubular blank from which the outer tubular member is formed;Figure 'I is a view showing the grooved mandrel inserted in therestricted bore provided at one comprising an outer member 2 formed froma cylindrical tubular blank 3 having a restricted bore 4 at one end, asbest shown in Figure 6. A suitable mandrel, generally designated by thenumeral 5, is inserted into the bore 4 and is provided with a pluralityof longitudinally extending ridges or ribs 6, as best shown in Figure 8.After the mandrel` has been inserted into the bore 4, as shown in dottedlines in Figure 6, the end of the blank 3 is swaged to force the metalconstituting the wall of the bore 4, into the longitudinal groovesprovided between the ridges 6 of the mandrel 5, as best shown in Figure8. The

mandrel is subsequently removed, whereby the -wall of the bore 4 will beshaped as shown in bore I3 provided in the tubula best showninFigure 2.r member 2 as which The core member 8 is relatively smaller in diameterthan the inside diameter of the tubular member 2, thereby to provide anannular chamber I4 between the outer and inner members 2 and 8, asshown. The core member 8 has a reduced4 cylindrical end portion I5adapted to be fitted into the grooved bore 4 of the tubular member 2, asshown in Figures 1 and 3, whereby the V-shaped grooves provided in thewall of the bore 4 become separated from one another to provide aplurality of preheating orifices I6, which are spaced apart equi-distantaround a central cutting gas passage I'I, provided in the core member 8.

An important feature of the invention resides in forming the V-shapedgrooves 'I in the wall of the bore 4, whereby the inner reduced endportion I5 ofthe core member need not be grooved or milled. By thusgrooving the wall of the bore 4, the cylindrical wall AI8 of the cuttinggas passage I'I, at the reduced end portion I5 of the core member 8, maybe made extremely thin, as shown, for example in Figure 9, whereby whenthe core member 8 is fitted into the grooved bore 4, the inner walls ofthe V-shaped orifices I6 are disposed in relatively close relation tothe cutting gas passage I1, so that when a preheating fuel gas isprojected. from the torch tip, such fuel gas will form substantially acontinuous cylindrical wall around the cutting gas passage I'I which,when ignited, will produce a highly concentrated preheating flame whichwill impinge directly against the area of the metal to be cut, wherebythe metal may be'quickly heated to a kindling temperature, which isessential before the cutting operation can be successfully started. I

By grooving the wall of the bore 4, as herein disclosed, the core memberneed not be grooved, whereby it may be made of copper, and whereby theentire torch tip, with the exception of the end piece Il, may be made ofcopper. 'I'his is advantageous in that an all copper tip will conductoil the heat more quickly than a tip which is -partially composed ofbrass or some other metal of low heat conductivity. Also, by making theentire tip of copper, the outside diameter of the tip may, if desired,be made relatively smaller,

which is desirable in tips to be used for cutting small rivets orcutting in close places.

From actual experience, I have found that by constructing the preheatingfuel gas orifices as herein disclosed, the wall I8 of the core member 8may be made to paper thickness, if desired, without danger of said wallmelting`or becoming distorted from excessive heat. This results becausethe inner member is made of copper which has a much higher melting pointthan brass, or other such metals. 'I'he end of the tip is shown providedwith a counterbore I9, as is customary in tips of this generalcharacter.

It will be apparent to those skilled in the art that I have accomplishedat least the principal objects of my invention, and it will also beapparent to those skilled in the art that the embodiments hereindescribed may be variously changed and modified, without departing fromthespirit of the invention, 'and that the invention is capable of usesand has advantages not herein specically described; hence it will be apupreciated that the herein disclosed embodiments are illustrative only,and that my invention is not limited thereto.

I claim as my invention: Y

A torch tip comprising an outer tubular member having a restricted borein one end, an inner member iitted within said tubular member and havinga reduced cylindrical end portion fitting in said restricted bore, saidinner member having a longitudinally disposed cutting gaspassagetherein, and the wall of said restricted bore having a plurality ofV-shaped grooves therein, the wider sides of which are deiined by theperiphery of the reduced portion of said inner member iitting in saidbore, said V-shaped grooves being parallel to and encircling saidcutting gas passage and cooperating to provide a plurality of preheatingfuel orifices from which a concentrated preheating flame may beprojected.

ELMER H. SMITH.

